The Dark Side of Dark Chocolate
It is well known that daily consumption of dark chocolate is beneficial due to its antioxidant properties as well as minerals, healthy fatty acids and psychoactive compounds such as caffeine. However, Consumer Report scientists recently measured heavy metal content in dark chocolate and the results called for serious reconsideration of how much of this healthy snack we should consume.
They specifically looked for the presence of cadmium and lead in 28 chocolate bars. They found the presence of these two heavy metals in all of them, albeit in varying amounts.
They concluded that 23 bars if consumed 30 grams or an ounce a day would put an adult over a level that public health authorities say may be harmful for at least one of those heavy metals. Five of the bars were above those levels for both cadmium and lead, while five had relatively low levels in both. The latter group would mean you could consume them in moderate amounts (30g/1 ounce) a few times a week relatively safely.
Check out the attached images and see if you can recognise a brand you purchase regularly. Even if you don’t it is highly unlikely that your chocolate doesn’t contain these two heavy metals. The only question is how much.
The Effects Of Heavy Metals
Regular exposure to heavy metals is linked to a host of health problems in children and adults. Pregnant women and young children are at the highest risk of exposure to heavy metals because they can cause developmental problems, affect brain development, and lead to lower IQ.
However, regular exposure to heavy metals can be harmful to anyone. It can lead to nervous system problems, hypertension, immune system suppression, kidney damage, and reproductive issues.
Even if you don’t eat dark chocolate every day as I do, lead and cadmium can still be a concern since they can be found in foods such as sweet potatoes, spinach, and carrots. Small amounts from multiple sources can add up to dangerous levels.
Why Are Heavy Metals in Chocolate
While all the health benefits of dark chocolate come from cocoa solids, that is also where heavy metals, especially cadmium, lurk.
Cacao plants take up cadmium from the soil, with the metal accumulating in cacao beans as the tree grows. That’s similar to how heavy metals contaminate some other foods. But lead seems to get into cacao after beans are harvested. The researchers found that lead was typically on the outer shell of the cocoa bean, not in the bean itself.
This means that manufacturers would have to tackle the problem differently for each metal. For lead, that would mean changes in harvesting and manufacturing practices. The researchers found that the lead content was low soon after harvesting and accumulated during the drying process. The manufacturers should thus minimise soil contact with beans as they lie in the sun, and dry beans on tables or clean tarps away from roads or with protective covers, so lead-contaminated dust won’t land on them.
Solving the cadmium problem is much trickier and it might require carefully breeding or genetically engineering plants to take up less of the heavy metal from soil. Additionally, removing or treating soil known to be contaminated with cadmium and replacing older cacao trees with younger ones would help, because cadmium levels tend to increase as the plants get older.
Some manufacturers blend beans from higher-cadmium areas with beans with lower levels. This is shown to be an immediate solution to the problem because blending different origins ensures that the final product has lower levels.
Smart Chocolate Consumption
While the Consumer Report article recommends that one of the ways to reduce heavy metal exposure is to consume chocolates with lower cacao content I would strongly argue against it. One of the main reasons we consume dark chocolate is to avoid sugars and additives present in chocolates with lower cacao content while harnessing all the benefits of this powerful plant.
Here are a few options to minimise the accumulation of heavy metals:
Reduce the amount of dark chocolate to a max of 30g a couple of times a week.
Find chocolate bars with lower amounts of cadmium and lead.
Eat a variety of fresh fruits and vegetables. Grapes, apples, green tea, and certain other healthy foods can even provide some of the same flavanols that chocolate supplies. Plus, doing this can help provide a variety of nutrients that may help offset some of the harm that heavy metals do. These include calcium, iron, selenium, vitamin C, and zinc.
Avoid eating dark chocolate if you are pregnant and avoid giving it to small children.
Think of your total cacao consumption. This might include cacao drinks, cake, brownie mixes, etc.
Detoxify from heavy metals on a regular basis. Sauna may help excrete heavy metals, says the researcher Dr Rhonda Patrick. Lead is excreted 14x more in sweat, and cadmium is excreted 11x more in sweat than urine. As mentioned you might be exposed to heavy metals through other sources, not just chocolate. Activated charcoal is also a good way of expelling heavy metals, but you have to be aware that it may expel many healthy minerals along the way.
Get tested for heavy metals in your body. While saliva tests might be more convenient and cheaper, they only provide a relatively short-term picture, since heavy metal values drop off quickly after exposure. A more long-term test would be from hair or nails. A simple Google search will offer a lab that does that near you.
Conclusion
It is hard to balance out the benefits of dark chocolate with its downside of heavy metal content. After all, dark chocolate has effects on improved blood vessel function, reduced inflammation, and lower cholesterol, it contains magnesium and potassium and has higher fibre content and less sugar than milk chocolate.
There is no clear cutoff point and people have different susceptibilities to heavy metal exposure. Awareness and informed choices are your best bet.
Consumer Report’s test results, after all, show that while contamination with heavy metals is common, it is not inevitable. We all vote with our purchasing choices and if we demand better quality chocolate the manufacturers will find ways to produce it.
Lastly, chocolate is not the most carbon-footprint-friendly choice for most of us Westerners so reducing the overall consumption will have a greater effect than just lowering your heavy metal exposure.
Resources:
https://www.consumerreports.org/health/food-safety/lead-and-cadmium-in-dark-chocolate-a8480295550/